Wenger believes they will bounce back from their defeat against Hull on Saturday, when they face Porto in the Champions League.
He said: “People are saying we are not good enough to win the Champions League but I believe we have enough quality to do it.
“I believe we will win tomorrow night. We want to make sure we win which means we must go into the game with the right belief.
“That’s what we want to show tomorrow night. Porto had a great win against Fenerbahce which shows you their quality, so we’ll be taking the match very seriously.”
He added on the Hull game: “We can’t make too much of it — we lost a game we did not want to lose.
“But we have enough strength inside the club to deal with that. It can happen — but it cannot be repeated.”